import java.sql.*;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
   //     m1();
//        m2();
//        m3();
       m4();
//        m5();
   }

    private static void m1() {
        //jdbc操作数据库
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        ResultSet resultSet =null;
        //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            //3.sql
            String sql="select * from user3";
            //4.预编译sql
            preparedStatement = connection.prepareStatement(sql);
            //5.执行sql
            resultSet = preparedStatement.executeQuery();
            //6.遍历结果
            while(resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"----"+name+"----"+pass);
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {
                if(resultSet!=null){
                    resultSet.close();
                }
                if(preparedStatement!=null){
                    preparedStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }

    private static void m2(){
        //键盘录入
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入用户名：");
        String name = scanner.next();

        //jdbc操作数据库
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        //1、 加载驱动
        try {
            Class.forName(" com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            //3.sql
            String sql = "select * from user3 where name like ? ";
            //4.预编译sql
            preparedStatement = connection.prepareStatement(sql);
            //设置参数
            preparedStatement.setString(1,"%"+name+"%");
            //5.执行sql
            resultSet = preparedStatement.executeQuery();
            //6.遍历结果
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id + "----" + name + "----" + pass);
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
            //7.关闭资源:从后往前依次关闭
            try {
                if (resultSet != null) {
                    resultSet.close();
                }
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
//添加
    private static void m3(){
        //jdbc操作数据库
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            String sql="insert into user3(id,name,pass) values(?,?,?)";
            //3.sql

            preparedStatement = connection.prepareStatement(sql);
            //设置参数
            preparedStatement.setInt(1,4);
            preparedStatement.setString(2,"张三");
            preparedStatement.setString(3,"123456");
            //5.执行新增
            int result= preparedStatement.executeUpdate();

            if (result>0){
                System.out.println("添加成功");
            }else {
                System.out.println("添加失败");
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {

                if(preparedStatement!=null){
                    preparedStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
//修改
    private static void m4(){
        //jdbc操作数据库
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            String sql="update user3 set name = ?,pass = ? where id =?";
            //3.sql

            preparedStatement = connection.prepareStatement(sql);
            //设置参数

            preparedStatement.setString(1,"王小明");
            preparedStatement.setString(2,"8888");
            preparedStatement.setInt(3,3);
            //5.执行新增
            int result= preparedStatement.executeUpdate();

            if (result>0){
                System.out.println("修改成功");
            }else {
                System.out.println("修改失败");
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {

                if(preparedStatement!=null){
                    preparedStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
//删除
    private static void m5(){
        //jdbc操作数据库
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            String sql="delete from user3 where id = ? ";
            //3.sql

            preparedStatement = connection.prepareStatement(sql);
            //设置参数
            preparedStatement.setObject(1,4);
            //5.执行新增
            int result= preparedStatement.executeUpdate();

            if (result>0){
                System.out.println("删除成功");
            }else {
                System.out.println("删除失败");
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {

                if(preparedStatement!=null){
                    preparedStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
}